Conventionally, a logistic system that conveys and stores articles under the control of a plurality of controllers connected with each other via a network (Japanese Laid-Open Patent Application 2003-264216, for example) is known.
The logistic system comprises, for example, a supervisory controller that is a high-level controller and a plurality of conveying controllers that are provided under the supervisory controller. A working area of a factory that has the logistic system is sectioned into a plurality of areas. In each area, a conveying device such as an automatic guided conveying vehicle or a conveyer and a device such as a communication apparatus are arranged. The conveying controller is arranged in each area. The conveying controller controls the transportation of articles under the management of the supervisory controller.
Conventionally, in such a logistic system, when the conveying controller is broken, the whole of the logistic system is stopped until the conveying controller is fixed. Then, a service man is sent to fix the conveying controller and replace the broken conveying controller with the working conveying controller. It should be noted that the broken conveying controller is monitored remotely via a telephone line.
It takes long time to fix the conveying controller by the above means. In addition, stopping the whole of the logistic system until the conveying controller is fixed causes the problem of lowering the productivity of the logistic system.